Pleura & peritoneum


Anatomy, history, grossing & features to report

Last author update: 1 December 2013
Last staff update: 23 June 2023

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PubMed Search: Pleura normal histology

Vaidehi Avadhani, M.D.
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Cite this page: Avadhani V. Anatomy, history, grossing & features to report. website. Accessed April 14th, 2024.
  • Lungs are surrounded by visceral pleural, a delicate serous membrane arranged as a closed invaginated sac
  • Inner chest cavity is lined by parietal pleural membrane
  • Visceral and parietal pleura define the pleural space / cavity, which normally has minimal volume, unless lungs collapse or air / fluid collects between the 2 layers
  • Only minimal contact between right and left pleural sacs
  • Regional lymph nodes are internal mammary, intrathoracic, scalene and supraclavicular

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Pleura and chest wall

  • Lined by mesothelial cells overlying vascularized connective tissue
  • Mesothelium provides smooth, low friction surface to facilitate the gliding motion of lungs in pleural cavity, heart in pericardial cavity, viscera in abdominal cavity
  • Gliding facilitated by numerous surface microvilli, thick glycocalyx, secretion of hyaluronic acid and other glycosaminoglycans
Mesothelial cells
  • Microscopic (histologic) description
    • Monolayer of flat or low cuboidal cells with bland and uniform nuclei, fine delicate chromatin, inconspicuous nucleoli
    • In fine needle aspirates, have well defined cytoplasm and distinct cell borders
  • Positive stains: keratin
  • Electron microscopy description: apical tight junctions, desmosomes, surface microvilli, cytoplasmic tonofilaments in bundles
Connective tissue cells
  • Microscopic (histologic) description: resemble fibroblasts
  • Positive stains
  • Electron microscopy description: resemble fibroblasts
Black spots
  • Carbonaceous / anthracotic pigments in parietal pleura
  • Present in > 90% of urban dwellers in Belgium at autopsy
  • Not related to hyaline pleural plaques (Am J Surg Pathol 2002;26:1198)
  • Associated with lymphatic drainage
  • Microscopic (histologic) description: deposits of opaque particles (intra or extracellular) of various sizes under an intact mesothelial layer, associated with chronic inflammatory cells
Types of specimen
  • Biopsy
  • Pleurectomy
Surgical procedures definition
  • Pleurectomy / decortication with mediastinal lymph node sampling
    • Complete removal of pleura and all gross tumor
  • Extrapleural pneumonectomy
    • En bloc resection of pleura, lung, ipsilateral diaphragm; may include pericardium
Grossing biopsy
  • If received for frozen section, ensure enough lesional tissue is present
  • Ask for additional tissue if tissue submitted needs to be entirely frozen
    • Important because immunohistochemistry may be unreliable on previously frozen tissue
    • May need to send for special studies including electron microscopy and cytogenetics
Grossing pleurectomy
  • Describe dimension and number of fragments, any lesions present
  • Note if pleural plaques are seen; describe
  • Tumor involvement of adjacent structures - lung, diaphragm, pericardium, skeletal muscle
  • Ink margins in sections closest to tumor
  • Tumor
    • One section per cm of tumor
    • Extensive sampling if desmoplastic mesothelioma is suspected
  • Additional sections of lung, if present (for asbestos fiber analysis)
    • Recommended (up to 5)
  • Sections for ancillary tests
    • Electron microscopy, cytogenetics, etc., if necessary
  • Lymph nodes
  • References: NCCN: NCCN Guidelines [Accessed 23 March 2018], Lester: Manual of Surgical Pathology, 3rd Edition, 2010
Features to report
  • Tumor size and location
  • Histologic type
  • Extent of invasion
  • Surgical resection margins
  • Involvement of pleura, pulmonary vessels, bronchus, mediastinal structures, diaphragm, chest wall, other
  • Lymph nodes: total examined, number involved by tumor, extracapsular extension
  • Presence of pleural plaques, ferruginous bodies, pulmonary interstitial fibrosis, other significant findings

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